Conventionally, disposable diapers, for example, have been known as disposable absorbent articles. The disposable diapers have been widely employed for babies and children to elderly persons and physically-handicapped persons, and have replaced reusable absorbent articles made of cloth. In order to enhance both the adhesion to users and cushioning properties, a stretchable composite sheet obtained by affixing two types of non-stretchable sheet members to each other with an elastic member, in an expanded state, having a shape selected from a thread shape, net shape, strip shape, sheet shape, or the like, sandwiched therebetween, to allow a degree of elasticity of a sheet member such as a non-stretchable nonwoven fabric has been used.
In a state where the elastic member in the stretchable composite sheet contracts, each of the sheet members has large wrinkles and pleats formed therein. The wrinkles and the pleats allow cushioning properties to be obtained. However, such large wrinkles and pleats irregularly appear on the nonwoven fabric with a random rigidity distribution of the nonwoven fabric. When the user wears such a disposable diaper, the disposable diaper is inferior in adhesion to the user and does not feel pleasant because a touch sensation is also preceded by feeling of rigidity.
In recent years, it has been reported that when large wrinkles and pleats continue to stimulate the skin, they affect the body as a tactile stimulus, which causes not only a feeling of discomfort but also an endocrine function and an autonomic imbalance and affects even intellectual development. Thus, there has been an urgent need to provide a disposable diaper having smaller wrinkles and pleats.
Japanese Unexamined Patent Application Publication No. 2002-238934, for example, provides a disposable diaper in which elastic threads for the body of disposable shorts are spaced 1 to 5 mm apart in a circumferential direction with the threads positioned between a front-side armored member and a back-side armored member in a body fit portion of disposable shorts and a vertically-long fine gather with a pitch of not more than approximately 3 mm is formed throughout the body fit portion.